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Reactions
How Do We Know How Old the Earth Is?
Season 4
Episode 31
Since there’s no “established in” plaque stuck in a cliff somewhere, geologists deduced the age of the Earth thanks to a handful of radioactive elements. With radiometric dating, scientists can put an age on really old rocks — and even good old Mother Earth. For the 30th anniversary of National Chemistry Week, this edition of Reactions describes how scientists date rocks.
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George tries to make a new discovery in a huge field of science... and he might have.

12:00
This week Alex takes to the lab and investigates the stable isotopes in 20 different honeys.

20:29
Rubbing two balloons together leads George to a shocking discovery.

11:25
Is baking soda a legal, performance enhancing drug?

8:10
George tries to make electricity using dialysis tubing, toilet parts, and a baby turbine.

13:59
Alex wonders what happens when hot water freezes quicker than room temperature water?

9:56
Could a seemingly magical 300-year-old technology save us from climate change?

14:50
Fluoride is everywhere in the discourse but here’s what the research actually says.

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How does a lifesaving drug vanish into thin air?

9:36
is there really a difference in the Coca-Cola from Mexico?

11:57
Alex made some kidney stones at home and tested prevention methods to keep them at bay.

10:38
An email from a subscriber made us question everything we thought we knew about trees.